Experimental Soft Condensed Matter Group Harvard University, Prof. D. A. Weitz Cool Picture of the Moment

This movie (taken by a fluorescent microscope) shows the gelation process of PMMA particles in a sample solution. You can see the initial gelation from the meniscus to the center of the solution. Then the gel boundary moves to the tip!!
Timescale: 1 second = 1 hour
Lengthscale: From the tip to the meniscus ~ 3 mm

For more information contact Susumu Inasawa.

Past cool pictures...